Method of shaping air filled rubber to form cushion grips for steering wheels



Jan. 2, 1940. M. B. RATNER METHOD OF SHAPING AI R LLED RUBBER TO FORMCUSHION G S F0 TEERING WHEELS Fi March 6, 1936 '2 Sheets-Sheet 1 NOB/W58. RA TA/E/f Jan. 2, 1940. RATNER 7 2,185,568

METHOD OF SHAPING AIR FILLED RUBBER TO FORM CUSHION GRIPS FOR STEERINGWHEELS Filed larch 6, 1936 2 Sheets-Sheet 2 MORRIS 8. RH T/VER I D IPatented Jan. 2, 1940 UNITED STATES 2,185,568 7 Y METHOD OF SHAPING AIR.FILLED RUBBER TOFORM CUSHION ING WHEELS.

GRIPS FOR STEER- Morris B. Ratner, Phoenix, Ariz. Application March 6,1936, Serial 1%.:67544 1 Claim; (01. 18 59) This invention relates to amethod of shaping air filled rubber and forming tubular structuresthereof capable of being used as a grip for a steering wheel of anautomobile or as a grip for other articlesfor which-it may be designed,the grip being so formed that when it is'in use it will fit snugly aboutthe article to which it is applied in close fittingengagement'therewith.

At the present time grips for entirely enclosing the rim of a steeringwheel or similar articles, areprovided, but they are made of rubber suchas is'used for making tires and'while they are 7 effective toa certainextent in preventing slipping and making driving easier, they have notproved 1 satisfactory. This is particularly true when used upon thesteering wheel of an automobile being driven at'high speed, the hands ofthe driver being practically in direct contact with the rim of the wheelexcept for the intervening layer of compact rubber, and vibrations willbe transmitted to the hands and arms of the'drivezy'and other portionsof the body will be affected by the vibrations passing through his arms;The driver has a tendency to grip the wheel and this will cause musclestrain and nervous reactions resulting in the driverbecoming very tiredafter continuing driving at high speed for a considerable length of.time.

It has been found'that ordinary. rubber heats and sweats the hands andfades to the hand, due to the excessive perspiration caused, and it isnot as durable as air filled or sponge rubber.

Attempts have been. 'made to form grips of air filled rubber known assponge rubber but have not been successful except when made of .shortflat strips intended to be secured about the wheel ri'mat points wherethewheel is usually grasped andsuch grips have notbeen foundsatisfactory as a persons hands will move off the grips when making aturn and it is necessary to maintain the hands in substantially astationary position upon the wheel rim. This is inconvenient and tiringto the driver.

Failure to make a success of forming a grip of sponge rubber which isadapted to entirely enwhen forming the improved grip for a steering thecore;

configuration to fit snugly about a steering wheel rim.

Therefore, an object of this invention is thedevelopment ofv a-methodwhereby aggripi adapted to extend, about and entirely enclose the rim ofa steering wheel maybe successively formed of sponge rubber and fitproperly thereon when inuse.

Anotherobject of the invention'is to providea method of forming spongerubber according to '1 which thestock willbe so disposed about a core inamold that as it expands when subjected to heat it will remain in'closecontact with the core and the grip when made will fit snugly about thearticle to'which it is applied."

Another :object .of the invention is to. produce a process of shapingair filled rubber whereby the I grip maybe made as an article to be soldas an accessory or formed directly about the rim' of a wheel, the wheelrim serving as a core during the making of the grip.

The invention isillustrated in the accompany- I ing drawings wherein: Yt Figure 1 is a sectional view of a mold used 5 wheel rim;

Figure 2 is a 'top plan View of the lower mold section with the core inplace;

Figure 3 is a view similar to Figure 3 showing the rubber stock appliedabout the core;

Figure 4 is-a view similar to Figure 1 but showing the mold closed andthe rubber stock about Figure 5 is a view similar to Figure 4 showingthe stock expanded about the core and filling the mold;"

Figure 6 is an enlarged fragmentary sectional view of the mold;

Figure .7 is a sectional view of a modified meth- 0d wherein a wheel ofmetal or hard rubber is placed inythe mold as a core and the grip formeddirectly about therim of the wheel; g Figure 8 is a View taken. alongthe line 88 of- Figure 'I'with a portion of the stock broken away;Figure 9 is a sectional'view of a second mold into which the wheel andapplied rubber are transferred after being removed from the mold shownin Figure 7;

- Figure 10 is an enlarged fragmentary view of Figure 9 showing therubber expanded and filling Figure 11 is atop plan viewof a steeringwheel havingqawooden; metal or composition rim to 5 which a grip hasbeen applied in accordance with another embodiment of this invention;

Figure 12 is a sectional view taken along the line iZ-IZ of Figure 11;

Figure 13 is a fragmentary sectional view illustrating the manner inwhich the grip shown in Figures 11 and 12 is molded about the metal orcomposition rim of the steering wheel; and

Figure 14 is a transverse sectional View through the grip portionshowing a modified form wherein the air-filled or sponge rubbercushioning member is covered by a thin sheet or layer of smooth ormechanical rubber.

According to the improved method of forming a steering wheel grip or thelike of sponge rubber, a mold is provided conforming to theconfiguration of the grip to be manufactured and in I the presentillustration a mold has been shown of theproper outline to form a gripfor the steering wheel of an automobile. This mold has upper and lowersections l and 2 formed of duralumin, steel, or other suitable metal.The two mold sections are of solid formation as shown in Figure 1, buthavetheir inner faces recessed, as shown at 3 and 4, to provide achamber 5 when the two sections are in engagement with each other andthe recess 3 of the upper section registering with the recess of thelower section, as shown in Figure 4'. The core 6 which may be formed ofaluminum, iron, steel, or other suitable materiaL-is formedwith orcarried by a plate l, and the plate and core are of such dimensions thatwhen the core is set in place, with the plate resting upon the centralportion El of the lower mold section, the core will extend centrally ofthe recess 4 and axially of'the chamber 5. It should also be noted thatthe plate I isof such thickness that when the two mold sections are inengagement with each other, the plate will :be engaged between thecentral portions of the two sections and firmly heldin its proper placeto maintain the core axially of the chamber 5.

Previously it has been found impossible to control expansion of thestock from which sponge rubber is made and cause it to move in theproper direction and form a hollow annular grip of the proper dimensionsand configuration. The stock is of a consistency similar to dough fromwhich bread is made, and according to this improved method the stock iscut to form stripsof. the proper length and width. One of these stripsof stock'is applied to the core, as shown at 51,.and is folded so thatit extends about the core in enclosing relation thereto with its marginsbearing against, upper and lower faces of the core plate I, as'shown inFigure 4. It is necessary to maintain the stock in close contact withthe core during expansion and curing of the stock and in order to do sothere have been provided pins 50- which project radially from the coreunder the plate l and are diagonally disposed at a converging angle.These pins are embedded in the marginal portion of the stock extendingabout the under portion of the core and they serve very effectively tohold the stock in close contacting engagement with the core. Instead ofpins, rings may be provided in the mold to hold the stock about thecore, or the core may be formed of twisted metal. After the stock hasbeen applied to the core and the core set-in place upon the lower moldsection, the upper mold section is applied to the lower mold sectionwhere it is secured in any desired manner. The mold is then subjected toheat and pressure of about three hundred pounds, and as the heat strikescarbon dioxspokes take the place of the core plate 1-. rim l3 whichserves as a core is of approximately the diameter of the core 1 and willbe centered ide in the stock it expands and convertsthe stock into aspongy mass having a large number of small cells therein. The carbondioxide gas does not es-i cape from the mold but where it strikes wallsof the mold sections, it forms a skin with small depressions or pocketsin the surface of the expanded stock and when the stock is fully cured,the grip H will have a pitted surface which has a soft feel when graspedin a persons hand and will not be liable to slip as the pits serve asvacuum cups and create a suction resisting sliding of the grip throughthe hands of a person holding a steering wheel to which the improvedgrip has 1 been applied. As the stock is held about the annular core bythe pins Iii it will remain in close 1 I contacting engagement with thecore and adjacent portions of the core plate and when fully cured willaccurately conform to the contour of the core. Therefore, when the moldsections are separated and the core and formedgri'p' removed therefrom,the grip will be of such size and con to each other and the grip will besecurely held in place about'the rim of the wheel. By providing ribsupon the walls ofthe chamber 5; the

figuration that. it will fit snugly about the rim of grip may be formedwith-ridges similar to thoseupon the tread of a bicycletire and mayserve to assist in preventing the grip from slipping through a personshand. P

It has also. been found that the grip may be directly applied to the rimof a steering wheel and a method of carrying out thisv embodiment of.the invention has been illustrated in Figures 7 through 13. The steeringwheel l2, shown in Figures 7 through 10, is formed of metal 'or hardrubber and when such a wheel is used its hub and The in thechamber Id ofa shaping mold 5. The

shaping mold is formed of upper and lower. sections which are separableinorder that the steering wheel may be secured between them after thestock Hi has been folded about its rim and the inner portion of thelower mold section has recesses l'l formed radially in its upperface toreceive spokes of the wheel. Thereforethe mold sections may have face toface contact'with' 'each. other and the mold be tightlyclosed. After-the1 mold has been closed it is subjected to suflicient pressure to set thestock about the rim and the mold sections then taken apart and the wheelwith the stock adhering thereto removed and transferred to a finishingmold is having a cham- 1 her IQ of approximately the diameter of thechamber 5-and of appreciably greater diameter than the covered rim, asshown clearly in Fi'gure 9. Sections of the mold iii are secured whenthe wheel is in place and the mold then subjected to heat which expandsthe stock to fill thecha'my 2,185,568 her or composition rim 22, thesurface of, the

rim should be roughened, as indicated at 23, so

' that the stock will adhere. to it. The stock 24 is applied about therim, as previously set forth, and the covered rim first supportedbetween sections of a forming mold and then transferred to a finishingmold 25in which the stock expands to fill themold chamber and forma grip26 of the desired size, or the Wheel having its rim' covered with stockmay be initially placed inthe mold 25 and the expanding and curing ofthe stock completed in one operation.

Under the process just described, the spokes of the steering wheel mayalso be cushioned, as well as the rim if desired, without departing fromthe spirit of the invention. -A replaceable unit for' the rubber portionof such grips may also be made as described. Such replaceable units whenmade, are preferably made over the same size as the desired rim,- only amould lubricant is used on the metal base so as to facilitate If. madeunder the last described process, the cushion is split on the innercenterwhich permits its rethe removal of the finished product.

moval fromthe cushion from the metal core.

' of soft sponge rubber for a steering wheel rim Should it be desiredthe sponge rubber stock comprising applying a strip'of sponge rubberstock about'the rim of 'a wheelior the entire circumference'thereof,applying the wheel to a mold having an annular chamber with the rimcentered in the chamber, subjecting the mold to pressure to evenlydistribute the stock and completely fill the mold and shape the stockabout the rim, transferring the wheel to a second mold having a chamberof. greater diameter thanthe chamber of the first mold and disposing thecovered rim in centered relation-to the mold chamber, and subjecting thesecond mold to .heat to expand the stock to completely'fill its chamherand cure the expanded stock to form a soft sponge rubber grip extendingentirely about and enclosing the rim.

. MORRIS B. RA'INER.

